The invention relates to smoke detector units and, more particularly, to apparatus securely connecting detector units to electrical systems in a home or building.
The risk and extent of property loss, personal injury, and death from fire and smoke can be minimized when smoke detectors are properly employed to provide warning during the initial stages of a fire. Laws in many jurisdictions require that smoke and/or heat detectors be provided in public and commercial buildings and private homes. This has led to the development of a wide variety of commercially available smoke detectors, some of which are battery operated and some of which are connected to the electrical system of a home or building by a permanent wiring connection or by reception of the male plugs on their power cords in female wall outlets.
A permanent wiring connection is preferable, but costly and difficult to install after construction of a home or building. A drawback of using a permanent wiring connection is the necessity that the smoke detector be connected at the location of the permanent wiring connection. This may result in the smoke detector being mounted in an inaccessible or non-ideal location. Smoke detectors that plug into a female wall outlet are susceptible to inadvertent removal from the female wall outlet. There may be excess length of power cord between the smoke detector and the female wall outlet. The excess length may be pulled, such as by a vacuum cleaner or a foot of person, thus pulling the male plugs from the female wall outlet and disconnecting the power supply to the smoke detector. The male plugs may also be removed from the female wall outlet for access to the female wall outlet by a user. This presents the risk that the user will inadvertently forget to reinsert the male plugs into the smoke detector, thus rendering the smoke detector inoperable.
Fire safety experts often recommend that smoke alarm detectors be placed on or near the ceiling of a room and preferably near the center. A problem with ceiling mounted detectors powered by batteries, rechargeable or otherwise, is that they are difficult to reach and deactivate in the event that the alarm is inadvertently triggered by a condition which is not dangerous. For example, ordinary cigarette and cooking smoke have the capability to trigger a smoke alarm, as does steam from a kitchen or a shower, and a triggered alarm will normally remain operative until the alarm triggering condition dissipates or someone deactivates the device. Furthermore, fire safety experts recommend that ceiling mounted detectors powered by rechargeable batteries be tested at least every six months to ensure that the batteries are still operational, and nonrechargeable batteries must be replaced fairly often.
Testing, recharging, and replacing batteries in a smoke alarm is often accomplished by pushing a button or other activating switch on the body of the detector. It can be difficult or impossible, however, particularly for elderly or infirmed persons, to reach ceiling mounted detectors or wall-mounted detectors at higher altitudes for these purposes.
Residential home owners who live in locations where construction codes do not require hard-wired smoke detectors or live in structures built prior to existing code requirements also may need smoke alarm detectors that are not powered exclusively by batteries. For example, a residential home owner may prefer the safety and convenience of having a hard-wired type smoke detector instead of having the inconsistent reliability of battery powered smoke detectors.
Prior smoke detectors have attempted to address the various problems facing battery powered smoke detectors. One such device is disclosed in U.S. Pat. No. 5,432,500, which discloses a smoke detector that is threaded into a light fixture, using the wiring thereto as its power source. While the disclosed detector does not depend upon batteries for operation, the detector may be inadvertently turned off by the light switch which controls the ceiling light fixture.
Despite the existing laws and building codes pertaining to smoke detectors, it is estimated that at least one-third of all battery powered smoke detectors are inoperable at a given point in time due to depleted or absent batteries. However, as many existing dwellings were not built to allow for hard-wired AC detectors and have no immediate means by which to utilize the more reliable AC models, they have been forced to rely on battery powered units.
In accordance with the present invention, an apparatus that provides uninterrupted power to a smoke detector unit from a home""s or building""s electrical system is provided. Unlike smoke detectors that are hard-wired to electrical systems, the present apparatus provides a home owner or building occupant significant flexibility in term of where to locate the detector unit while still securing uninterrupted access to the power provided by the electrical system of the home or building.
In a preferred form, the apparatus includes a power supply line of adjustable length with an integral outlet cover plate and male plug blades at one end. In this manner, one can remove the existing cover plate, insert the male plug blades into the wall outlet, and fasten the integral cover plate to the wall or ceiling to prevent accidental disconnections of the power supply line from the electrical system of the home or building. Another form of the apparatus allows a user to use the female socket of a standard lamp to provide uninterrupted power from the electrical system to the smoke detector unit via a blocking member of the smoke detector unit that covers the lamp switch in the on position, and an outlet cover that maintains the lamp cord plugged into the wall outlet. In yet another form of the apparatus, one can use the apparatus with the wiring of a light fixture. Either a protective sheath can be provided on the smoke detector unit for covering a switch, e.g., a pull chain, at the light fixture, or a wall switch faceplate can be used for covering a standard wall switch. In this form where the blocking member is the wall switch faceplate, the smoke detector unit can include a socket connected to internal power circuitry, and the wall switch faceplate can include a radio transmitter with a switch for sending a radio signal to receiving circuitry that provides power through the internal power circuitry to a female lightbulb socket formed in the smoke detector unit.
As is apparent, the present apparatus allows considerable latitude in determining the location of the smoke detector unit rather than having the location preset as dictated by a permanent wiring connection, placed by a home builder or the like, while still securing access to uninterrupted power from the electrical system of a home or building unlike prior plug in types using only power cords. In various forms, the apparatus allows the user to change the length of the power supply line to allow the unit to be mounted at various locations without excess length of the power supply line exposed for accidental contact by a vacuum cleaner or a person""s foot. The locations can be remote from the wall outlet, or next to any lamp in the home or building, or using the wiring for any light fixture in the home or building. In each of the above-described forms, substantially uninterrupted power from the electrical system of the home or business to the smoke detector unit is maintained by way of an integral mounting plate or a blocking member and/or outlet covers.
In a preferred form of the invention the smoke detector apparatus includes a small, portable smoke detector unit that is capable of installation in the home or building. The smoke detector unit has a smoke detecting mechanism therein. The smoke detecting mechanism may comprise ionization type detection and/or photoelectric detection. An audible alarm is provided for sounding when the smoke detection mechanism detects dangerous amounts of smoke in the home or building. The smoke detector unit contains electrical circuitry for receiving power to operate the smoke detecting mechanism and the audible alarm.
A power supply line is provided to connect the smoke detecting unit to the electrical system of the home or building. A first end of the power supply line has a mounting plate intergrally formed as by molding thereon. The mounting plate is in the form of an outlet cover plate including openings for allowing male plug blades to be inserted into the standard female electric socket of the wall outlet of the electrical system of the home or building. The first end may also have a standard female electrical socket formed thereon. A second end of the power supply line is electrically connected to the smoke detector unit to provide power to the electrical circuitry of the smoke detector unit. The power supply line may be cut to tailor its length so that it extends between the mounting plate and the smoke detector unit wherever the smoke detector unit is mounted in the home or building. The mounting plate replaces the existing cover plate of the wall outlet and is fastened to the wall so that male plug blades carried thereby and electrically connected to the power supply line are secured in the female electric socket.
The smoke detector unit may have a xe2x80x9cquick connectxe2x80x9d feature for electrically connecting the power supply line with the electrical circuitry of the smoke detector unit. The xe2x80x9cquick connectxe2x80x9d feature may include push down tabs that make electrical contact with the power supply line.
A conduit is also provided for attaching a portion of the power supply line between the ends of the power supply line to a wall or other surface of the home or building. The conduit can be cut to the necessary length to cover the portion of the power supply line. The conduit may be attached to the wall using an adhesive backing on the conduit. The conduit may be formed of extruded plastic and may be generally U-shaped in cross section for receiving the portion of the power supply line therein.
The mounting plate is adapted for fitting over a standard wall outlet electrically connected to the electrical system in a home or building. The mounting plate may be formed in a decorative shape, such as a fire truck or a cartoon character for use in a child""s bedroom. The wall outlet may have one or more electric sockets. An existing outlet cover in a home or building may be removed and replaced with the mounting plate. The interior of the mounting plate has male plug blades electrically connected to the first end of the power supply line for insertion into the electric socket of the wall outlet to supply power from the electrical system to the electrical circuitry of the smoke detector unit. Fastening the mounting plate to the wall outlet provides a secure connection between the electrical system of the home or building and the smoke detector unit. When the mounting plate is fastened to the wall outlet the power supply line resists accidental removal from the electric socket. For example, accidentally pulling the power supply line, such as by engaging it with a vacuum cleaner during ordinary cleaning or inadvertently tripping over it with a person""s foot, will not interrupt the power supply to the smoke detector unit.
The mounting plate may have an opening for access to an electric socket of the wall outlet not occupied by the plug blades. This allows users to use available electric sockets on the wall outlet for other uses while still maintaining the power supply line in connection with the electrical power system of the home or business. The mounting plate can also include a retractable cover to block access an open electric sockets on the wall outlet. This is particularly useful in homes or buildings where small children may be present to prevent electrocution. The retractable cover may have slots for insertion of the male end of an electric cord. The retractable cover may have an integral spring system to force the slots out of alignment with corresponding slots of the electric socket. A user could insert the male end of an electric cord into the slots of the retractable cover and rotate the retractable cover back into alignment with the corresponding slots of the electric socket.
In one form, the smoke detector unit has a non-standard female power outlet formed thereon. The non-standard female power outlet provides electrical power between the electrical circuitry of the smoke detector unit and an accessory. The accessory is designed with a non-standard male plug for insertion into the non-standard female power outlet of the smoke detector unit.
The accessory may have a light for indicating that power is being supplied to the accessory and thus the smoke detector unit.
The accessory may comprise a battery for providing back-up power supply to the electrical circuitry of the smoke detector unit. In the event that the electrical system of the home or building does not supply power to the wall outlet the battery will supply power to electrical circuitry of the smoke detector unit. The accessory may have a battery charger for maintaining the battery at full strength with power from the electrical system of the home or building. The accessory may also have a clock for displaying the time. The clock also provides a visible indication that the smoke detector unit is receiving power from either the battery or the electrical system of the home or building. A light may also be provided on the accessory for indicating when the battery is supplying power to the smoke detector unit and the electrical system of the home or building is not operational.
Other accessories may also be provided for attachment to the smoke detector unit. For example, the accessory may comprise a carbon monoxide detector for alerting when dangerous levels of carbon monoxide gas are present in the home or building. The accessory may alternatively comprise a nightlight for providing illumination. Multiple accessories may be attached to each other using non-standard female power outlets similar to that of the smoke detector unit formed on each accessory. The accessory comprising the nightlight does not have such a power outlet so that it may be used on the end of another accessory or the smoke detector unit without the danger that a small child may be electrocuted by contact with the power outlet.
In another form of the invention, an apparatus is provided including a small, portable smoke detector unit with electrical circuitry therein electrically connected to an intermediate conductive member for supplying power from the electrical system. The intermediate conductive member may include a standard lightbulb socket, such as on a lamp or a ceiling fixture. The intermediate conductive member may also include electrical power leads. The smoke detector unit may have a xe2x80x9cquick connectxe2x80x9d feature formed for receiving the power leads. The xe2x80x9cquick connectxe2x80x9d feature may comprise push down tabs that make electrical contact with the power leads.
Power from the electrical system of the home or building to the intermediate conductive member may be controlled by a switch operable by a user between on and off states thereof. In one form the smoke detector unit has male socket threads formed thereon for insertion into the standard lightbulb socket to provide an electrical connection between the standard lightbulb socket and the male socket threads when the switch is in the on state. The smoke detector has a blocking member integral therewith for preventing access to the switch and preventing the accidental operation of the switch by a user from the on to the off state.
A standard female lightbulb socket may be formed in the smoke detector unit for receiving the lightbulb. The socket is electrically connected to the internal power circuitry of the smoke detector unit. The electrical circuitry constantly supplies power to the smoke detecting mechanism and the audible alarm mechanism of the smoke detector unit. The internal power circuitry electrically connects the electrical circuitry and the female lightbulb socket. The internal power circuitry may be switched on and off so that power may be supplied to the female lightbulb socket such that the lightbulb in the female lightbulb socket may be turned on or off without turning off the power from the electrical system of the home to the electrical circuitry of the smoke detector unit. The smoke detector unit may have a hoop integral therewith, the hoop being adapted for attachment of a lampshade to cover the lightbulb inserted in the female lightbulb socket formed in the smoke detector unit.
For a switch mounted to a lightbulb socket on a standard ceiling fixture or on a lamp, the blocking member of the smoke detector may comprise a protective sheath that surrounds the switch to cover the switch in the on state and to prevent access thereto. For a switch mounting to a wall, such as a standard ceiling light switch, the blocking member may comprise a switch plate cover. The switch plate cover may have a recess therein to cover the switch in the on state and to prevent access thereto.
A fixture switch operatively associated with a radio signal transmitter may be provided. For example, the switch plate cover may have the fixture switch formed thereon. The fixture switch may comprise a push button or a replica of a standard toggle found on most wall switches. The transmitter may signal a receiver in the smoke detector unit upon operation of the fixture switch to operate the internal power circuitry of the smoke detector unit to provide power from the electrical circuitry of the smoke detector unit to the socket of the smoke detector unit. Such a fixture switch allows for the activation of a lightbulb in the smoke detector unit without adding any additional electrical wiring to the electrical system of a home of building while maintaining uniterrupted power from the electrical system to the smoke detector unit.